package ch4;

public class Example4_9 {
    public static void main(String args[]) {
        SIM simOne = new SIM(13889776509L);
        MobileTelephone mobile = new MobileTelephone();
        mobile.setSIM(simOne);
        System.out.println("手机号码:"+mobile.lookNumber());
        SIM simTwo = new SIM(15967563567L);
        mobile.setSIM(simTwo);
        System.out.println("手机号码:"+mobile.lookNumber());
    }
}

class SIM {
    long number;
    SIM(long number){
        this.number = number;
    }
    long getNumber() {
        return number;
    }
}

class MobileTelephone {
    SIM sim;
    void setSIM(SIM card) {
        sim = card;
    }
    long lookNumber(){
        return sim.getNumber();
    }
}
